Modified vaginal dilation rat model for postpartum stress urinary incontinence

Area of Science:

• Urology
• Reproductive Medicine
• Animal Models

Background:

• Postpartum stress urinary incontinence (SUI) significantly impacts women's quality of life.
• Existing animal models may not fully replicate the complexities of postpartum SUI.
• There is a need for reliable and easily established models to study SUI pathogenesis.

Purpose of the Study:

• To develop a modified rat model for postpartum stress urinary incontinence (SUI).
• To ensure the model is easily established and can reliably evaluate urodynamic changes.
• To provide a tool for studying the mechanisms of postpartum SUI.

Main Methods:

• A rat model was created by inflating a vaginal balloon for 8 hours to simulate labor.
• Sneezing was induced to assess SUI via leak point pressure (LPP) and maximum bladder volume.
• Serum markers (LDH, CK) and pubococcygeus muscle caspase-3 mRNA expression were measured to assess muscle injury.

Main Results:

• The model successfully established postpartum SUI in 72.5% of rats after 8 hours of vaginal dilation.
• SUI was consistently observed in the sneeze assay, with varying percentages over 56 days.
• Elevated serum LDH and CK levels, and increased caspase-3 expression in pubococcygeus muscle were observed, indicating muscle injury.

Conclusions:

• Eight hours of vaginal balloon dilation is effective in creating a rat model for postpartum SUI.
• The observed biochemical and molecular changes in the rat model correlate with those in human postpartum SUI patients.
• This model serves as a valuable tool for investigating the pathogenesis of postpartum SUI.